[ndiddy]

The same person who did this project also worked out how to compile the Lisa Office System code Apple released: https://github.com/alexthecat123/LisaSourceCompilation This took a lot of work because Apple didn't release any of the tooling required to build the code, and the code was actually too big to fit on a stock Lisa hard drive (the hard drive is 10 MB, the code is ~20 MB) so they had to hack the OS to patch in support for higher capacity drives.

It’s neat that there’s such passionate Lisa fans out there. If anyone here is a current day Lisa enthusiast, I’m curious what makes you interested in it.

[AlexTheCat123]

My interest mainly just comes from the Lisa's unique architecture, both in terms of hardware and software. As I learned during my LOS compilation efforts, the OS was quite advanced for its time, and many of the decisions made in the hardware design (like soft power and the discrete-logic MMU) were quite impressive and advanced for a personal computer. I had already done the software side of things during my LOS compilation project, so I figured that the next logical step would be to recreate the hardware within an FPGA!

[ndiddy]

Yeah from a technical perspective it's really impressive for its era. OS written in a high level language, preemptive multitasking, memory protection, stuff like that. I just wish there was more software available for the Lisa. It's a shame that Apple gave this all up for the Mac, it severely limited that platform as the computers grew over time. It would have been neat if Apple had based their larger computers (Mac II, etc) on Lisa OS and provided some sort of compatibility layer that programs intended for classic Macs would run inside.

[AlexTheCat123]

I know. In a lot of ways (at least at an architectural level), Mac OS didn't fully catch up to the Lisa OS until the release of OS X, which is pretty crazy to think about. I'm hoping that this board will make the Lisa dev tools more accessible to a people (and also a lotttt faster) and maybe that'll inspire the development of some new Lisa apps!

[yjftsjthsd-h]

> and the code was actually too big to fit on a stock Lisa hard drive (the hard drive is 10 MB, the code is ~20 MB) so they had to hack the OS to patch in support for higher capacity drives.

Then how was it originally developed? Did Apple also patch their own OS?

[ndiddy]

Apple hooked up the Lisa to a much larger larger external hard disk, the Priam Datatower. It could hold ~84 MB. The Datatower is extremely rare and AFAIK nobody with the skills to figure out how it works for emulation or cloning has a working one with a Lisa interface card.

[yjftsjthsd-h]

So then the OS did support higher capacity drives, just not anything that anybody can use these days

[ndiddy]

The OS did, but the disk driver for the Lisa ProFile hard drives (which was distributed as part of the OS) did not. All existing emulation only supports the ProFile drives, not the DataTower. If you're actually interested, I think it would be a better use of your time to look at the readme file for the repo I linked (which goes over the patch) instead of nitpicking my comments.

[yjftsjthsd-h]

I didn't mean to nitpick, I was actually confused and curious. And I'm willing to believe that it's discussed in that repo, but that's a lot of text to go through.